The constant term in the expansion of $\left( x^{2} - \frac{1}{x} \right)^{9}is$

Question

Dr. Abubacker · Accepted Answer

(c)
$T_{r + 1} = \ ^{9}C_{r}{(x}^{2})^{9 - r}\left( - \frac{1}{x} ight)^{r}$
$= \ ^{9}C_{r}x^{18 - 2r - r}( - 1)^{r}$
For term independent of $x$, put $18 - 2r - r = 0 \Longrightarrow r = 0$
$	herefore\$Constant term, $T_{7} = \ ^{9}C_{6}{( - 1)}^{6} = 84$

Q. The constant term in the expansion of $\left( x^{2} - \frac{1}{x} \right)^{9}is$

Explanation

Reviewed by Dr. Abubacker

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